A typical in-vehicle navigation system includes a receiver which receives position determination data from satellites, a microprocessor, a display and a map database. Typically, the position determination data is received from global positioning system (GPS) satellites which are a part of the GPS satellite network. The position determination data is processed via an electronics package located within the receiver or by the microprocessor unit. Most prior art in-vehicle navigation systems are self contained and do not interface with any outside sources other than the fact that they receive GPS data.
Other prior art systems such as the navigation system disclosed in U.S. Pat. No. 5,452,212 entitled "NAVIGATION SYSTEM FOR VEHICLE" involves the placement of numerous expensive components inside the vehicle. The '212 patent discloses a navigation system which includes a GPS receiver, data storage, an input section (touch screen), a display, a speaker system, and various other components which are located within the vehicle. The driver obtains information from a display screen which displays a whole route map and the names of the landmarks within the whole route map. Alternatively, the '212 system provides vocal instructions which are emitted by a speaker to the driver of a vehicle. In the '212 system, navigation information is generated within the vehicle from a database stored in a data storage section. The database includes geographical information, guide information about landmarks, data used to provide displays for guiding the driver, and other data. This system also includes a present position-location section which determines the present location of the vehicle from information received by GPS receiver and geographic information stored in data storage. In addition, the prior art '212 system includes a controller (arithmetic section) and a speech processor which translates information from the controller into analog signals so as to generate speech which is transmitted through speakers to the user. Hence, the prior art '212 system requires an extensive storage mechanism to store the geographical information, the landmark information, the speech generation program and the navigation data needed for calculating route data. As a result, prior art systems such as the '212 system are expensive and are difficult to maintain and operate. That is, each vehicle employing such a prior art system must maintain a complete and extensive database and an expensive microprocessor and speech processing system.
Additionally, in such prior art systems such as the '212 system, the data stored in each vehicle must be frequently updated to provide an effective navigation tool and the updating is expensive and time consuming. Even when data in this type of system is updated weekly or monthly, the system is not able to deal with current travel conditions such as weather conditions and temporary problems such as roadway repair, rush hour traffic, and traffic accidents. This is because these types of changes are unpredictable, quick, and transient. A road may be closed for repairs for the day, blocked by a fallen tree, or full of snow, and such changes are usually short lived. Thus, in order to fully meet the needs of a user, the navigation system needs the ability to change dynamically.
One prior art system which provides real time routing is disclosed in U.S. Pat. No. 5,177,685 entitled "AUTOMOBILE NAVIGATION SYSTEM USING REAL TIME SPOKEN DRIVING INSTRUCTIONS" which discloses the use of a computer (either installed in the automobile or accessed through a cellular car phone), input means, data storage (CD ROM), a vehicle location system, discourse generating programs and speech generating programs. The prior art '685 system further includes a map database and a route finding algorithm, both of which are stored in data storage. Based on the current position of the automobile and the route, the discourse generating programs compose driving instructions and other messages according to a discourse model in real time. The driver instructions and other messages are sent through a voice generator to the driver. The prior art '685 system uses CD ROM disks for storing data. CD ROM disks are a relatively inexpensive means for storing data and they are easy to install. Thus, storing the required data on the various geographic regions and updating the data is less burdensome for each in-vehicle computing system. However, the disks carried with each in-vehicle computing system should be frequently updated and old disks must be discarded. This results in additional recurring costs which may be quite significant. In addition, whenever a user having an in-vehicle computing system desires to travel into a region other than the region in which they normally travel, they must purchase a new disk or set of disks for each new region.
In-vehicle computing systems such as the '685 system are expensive to manufacture and keep updated, particularly when numerous in-vehicle databases must be continuously updated for changes to conditions. The burden of the updating requirement is particularly apparent when one considers that on any given day numerous events transpire in each city and region. In order to keep an in-vehicle system updated such that the vehicle could travel across a country, thousands of changes must be input on a daily basis into the vehicle. This requirement is particularly burdensome in light of the fact that most users only are traveling locally and they do not need to use the updated information occurring in other cities and states. In fact, particularly in large cities and major metropolitan areas, the user does not require all of the information updates in their particular city since they may not be planning to travel to a particular neighborhood or part of the city to which the update pertains. Therefore, most of the updated information which is stored in the navigation system is never used and if it is used, it is used infrequently. Thus, because the cost of keeping each system updated is high, and because most of the updated data is not used on a daily basis, such a prior art system is not cost effective.
The prior art '685 system which accesses a computer via cellular phone is expensive to operate since the cellular car phone line must remain open in order to transfer real time location data to the computer and must remain open to relay real time instructions from the computer to the user. Also, since each user must maintain his own cellular phone line, many phone lines must be kept open simultaneously. Additional expense is incurred because the location housing the computer must maintain an extensive number of dedicated phone lines and information from each phone line must be constantly monitored and processed by the computer. The '685 system would be particularly expensive for users driving long distances since the user may not need instructions for hours at a time.
However, in order for a vehicle communication and navigation system to be truly effective, the user must have access to other information and services. For example, the '685 system also discloses the use of the vehicle navigation system for locating a parking lot and discloses that the system could automatically call a parking garage by phone or radio to reserve a space. Using prior art methods to store information regarding these types of service and the updating of those services on particular navigation system computers located on individual vehicles requires more data storage than is currently available in portable computer systems and CD ROM drives. Thus, the cost of such a system is prohibitive.
What is needed is a way to provide a user with navigation and other services on a cost effective basis without the need to update numerous individual in-vehicle databases with superfluous information. In particular, what is needed is a vehicle navigation system which includes inexpensive in-vehicle components; a system which is easy to operate; a system which allows for cost effective installation, maintenance and updating of data; and a system which provides needed data on a real time basis. More specifically, a vehicle navigation system which includes a location determination system and which will reliably operate in a variety of locations without the need to manually update an extensive map database inside the vehicle is required. In addition, a vehicle navigation system which draws from a database which receives updated information on a real time basis and which may be easily kept current is required.